Backyard Aquaponics
A place to discuss aquaponics

Okay it's been two months now, where are the pictures Doug? I am interested in growing cold water fish in the next system - what would you recommend based on your experiences?

I am just coming off a long engineering contract. I have not been on-line much...too busy. Also, my AP filter broke down and I am in the process of replacing it.

From my experience, hybrid blue gill are a good choice for cold water. Mine eat down to 45F. And they are eating vigorously with the water at 50F. They actually grow over thwe winter. I plan to harvest around Sept (at 18 months after arrival (4" fingerlings). My channel catfish are fine, but are not eating at 50F (I expect them to resume eating at about 55F. They make good growth above 60F and I will harvest them too in Sept (18months from 6" fingerlings). I am going to take pictures of my new filter and will collect some general picture to put on my web site and announce them here. Probably another week or two (contract ends then and just in time for spring garden work.

Kthx! Looking forward to it!

Hay Doug,
How's spring treating you and your system?

I just got down to reading through your thread again. Did you ever manage to do a copper test?
Though I guess it worked out that the catfish losses were probably due to disease right?

I have 45 catfish in my system now and am really worried for them as I think they are suffering from some sort of bacterial or viral disease. No Deaths from the disease yet though.

Hello Dave;
I have had good luck with a combination of hybrid bluegill and channel catfish. They get along fine and you are using two levels of the tank water. The catfish are on the bottom and the bluegills are using the mid levels. Feeding floating food has worked fine. The catfish will come to the surface when they are hungary and they also police food on the bottom. My catfish reached 13-14" from 6" fingerlings in 17 months and averaged 1.5 lbs. They filleted nicely. This is with no artificial heat, so winters the water temp was about 42F. In the summer water temp was never above 74F. My tank is 6' deep with 3' in the ground, so natural earth cooling was holding the temp down in summer and up in winter. The hybrid blue gills at 17 months could have used more time or warmer water to grow larger. They were between 6oz and 1 pound (big range for fish from the same fingerlings of 3-4"). They were too small to fillet and we are cooking them bone in. They are hard to eat that way, so I would allow them to grow from May of year one to Sept of year three to take advantage of three summers of growth (30 months) so I can fillet them. That sure makes Tilapia sound good!
Have you started your operation with cold water fish yet?

Doug

Sorry, I really did 'fall off the earth'. So, one year later...how did the catfish do?

I am in the process of cleaning my tanks to seal them with a double coat of UGL DryLok concrete waterproofing paint. I finally found the cause of my pH being buffered over 8 such that any amount of phosphoric acid or acetic acid added would pop from pH 7 to 8 over night. It was not the concrete, which agrees with the people that told me they had no problem with concrete tanks. My problem was a treatment I put on the tanks when they were new. I put a Radon sealer on the concrete (mine was Radon Loc, another brand is Radon #7). The makers of Radon #7 sent me literature that gives technical info that says the pH of this chemical is 11.3 and will leach out indefinitely. There is my problem! I also found that you can not put Permiflex Urethane over this coating...it will not adhere. You must sandblast it off and it has deeply penetrated the concrete, so I will not be doing that. Thank you Dave Donnelly for giving me the lead to Permiflex Urethane coating (it would have been perfect on raw concrete). I found that you can paint over the Radon treatment, so I will attemp to seal it off with UGL Dry Lok. If that peels off, then I have big problems!

Doug,

If worse comes to worse, then you could always just use a plastic liner. I had to do that when I had a similar issue.

Mathew

Do you have a round tank? If not, how did you get a liner fit in corners?

I just fold it in my rectangle tanks, TCLynx has a post about folding liners viewtopic.php?f=8&t=5103. Folding liners works well, don't try cutting and bonding, others have had hard to find leaks doing that. The only problem I have ever had was the small fingerlings sometimes hide in the fold and one once got stuck and died.

Bugger
That Radcon7 is a reactive chemical..
when water touches it, it swells.
I have never used it, and prolly never will

It has its uses for Radon in basements. I had not seen the tech literature on the gel effect. I thought it would be affectively inert after it reacted with the concrete.

I am learning from my mistakes...hopefully I can help others not make the same ones.

I like the fish tank. Did you have any photos of how it was made.

Perhaps I can find construction pictures, it was poured in 2004. I will look at my old pics and see. But remember, a thousands words are worth a picture...or something like that The floor of the tank was poured three feet below grade with steel mesh and rebar. In the perimeter of this was laid vertical rebar and a 12" wide vinyl strip with ribs to grab the concrete. Three days later the walls were poured over the exposed rebar and the top of the vinyle strip. The contractor said the joint would leak without the vinyl strip. Normally basement forms have thru rods used to keep the forms from bulging out under the weight of the concrete. We did not want to plug these holes in the walls (leaks). The vertical forms had no thru rods and was heavily braced inside and out to prevent bulging. The forms were custom built with plywood and lots of 2x4s and 2x6s. The time and materials for the custom forms made it expensive. I paid $11,000US for the tank and floor with 4x8 foot sheets of 2" foam insulation board around the exterior. Footings need to be 42" here for frost heave. We went 48" to match the foam board. The concrete was a six bag mix with a plasticizer to rest cracking. The concrete was vibrated into forms to eliminate bulbs and voids. So far no cracks and no leaks. With my new rubberized coating, it will not even absorb water.

Hay Doug, I saw your post in John's system about your troubles with fish dieing and the coating.

I wonder if the people using this coating for fish tanks are washing it with some special cleaner before rinsing really good before putting the water for fish into the tank?

Hopefully the trouble goes away since having to wait till fish are gone and then warm weather to drain it and wash it again the rinsing really well before re-starting will be another huge undertaking.

The fish loss has stopped completely. I have not lost any fish in July and August. I have about 60 catfish and 12 hybrid blue gill left. They are growing and eating well. I will never know what killed over 400 fish. Now the grow out will take until September of 2010. Not much of a harvest this time. Probably about 40 lbs of fish fillets. Again the fish will cost about $12/lb. The plus side is all the fresh veg I get during the snowy Michigan winter. We have a hot tub in the greenhouse & winter soaks surrounded by the veg and listening to the water flowing into the sump is very nice. My chickens love the waste greens from the bya system. In spring 2011, I will stock 200 channel catfish only. The catfish are the most hardy and provide a pound of fillet from each 2 pound fish. If I harvest 200 pounds of fillets, then the system is where I want it to be.

Meanwhile, we are getting two 40 lb feeder pigs in spring 2010. They will grow to 225 lbs by Nov 2010. That takes 2400 lbs of feed. I will buy some pig feed, but to a large extent, I want to grow feed and allow grazing behind electric fence. This year I grew soy beans, field corn, mangel beets, and sugar beets. They grew well and the chickens also like the mangels and sugar beets. Next year, I will use the corn, soybeans, and beets to feed the pigs. They eat the greens and the roots. The gardens of human food also did well this year. We have canned 400 jars so far and we are still doing tomatoes, potatoes, stews, and squash. The winter squash and potatoes are yielding well. We now produce about all we need. A lot of work! I have great equipment to help me. I have great respect for the pioneers that did this with so little equipment.